An electrostatic-capacitance-type touch panel detects change of an electrostatic capacitance induced by an object approaching the panel surface, and converts information about the position of the approaching object on the panel surface into an electric signal. Since a conductive substrate used for such an electrostatic-capacitance-type touch panel is installed on the surface of a display, a wiring material of the conductive substrate needs to have a low reflectance and a low visibility.
Thereupon, as a wiring material used for an electrostatic-capacitance-type touch panel, a material having a low reflectance and a low visibility is used, and the wiring is formed on a transparent substrate or a transparent film. For example, Patent Document 1 discloses a transparent conductive film for a touch panel that has an ITO (indium tin oxide) film formed as a transparent conductive film on a high-polymer film.
In recent years, displays having touch panels have been becoming larger, and hence, larger areas have been desired for conductive substrates such as transparent conductive films and the like for touch panels. However, ITO has a high electrical resistance that causes degradation of a signal, and hence, has a problem that it is not suitable for a larger panel.
Therefore, for example, as disclosed in Patent Documents 2 and 3, ideas have been considered that use metal foils such as copper films and the like instead of an ITO film. However, for example, if copper is used in a metal layer, there is a problem that metallic luster of copper reduces visibility of a display due to glitter caused by reflected light.
Thereupon, a conductive substrate has been considered that has a metal layer constituted with a metal foil such as copper film or the like, and in addition, has a blackened layer formed to prevent reflection of light on the surface of the metal layer.